Front Brakes

[ljonesjo]

Hello all. We did our first 100k on a tandem this weekend. It is also the first time we have had a ride with a steep winding descent. I noticed alot of front wheel shudder while braking. We have a KHS tandem. It has Tektro linear pull brake calipers. I had already added brake boosters and Kool Stop (Mathauser) pads. Braking power is more than adequate I just don't like the shudder. The Tektro calipers have a little bit of slop in the attachment to the brake posts. Is this normal for linear pull brakes? I am used to braking primarily with the front brake, but I notice that many tandems come with only a disc brake on the back. Is it better to emphasis rear braking on a tandem? Just so you have the full story, we are not a lightweight teams out combined weight (riders + bike) is 430#. Any feedback or advice is appreciated.

[sch]

Judder happens but should not. 1) check toe in and shoe contact angles at the rim
2) check the rim for any bulge or damage 3)scotch brite the rim with a bit of soap
and thoroughly clean the rim 4) (get new pads but you did that).
Front brake only is potentially dangerous on a singleton but is a much more effective
brake because of weight transfer forward in braking. On a tandem this is less true
and rear brakes can be highly effective. Our team is a bit lighter at 360 but the
rear disk does a superb job

[zonatandem]

Also, check if your headset is properly tightened. If even a tiny bit loose, will create fork shudder when braking.
Because of short cable run, front brake is the best stopper. Discs are primarily on rear of tandem as front disc can create other issues.

[RacePhase]

I'd guess its the headset as well. You could easily figure that out by pulling the front brake and placing your fingers on your headsets upper bearing cup and move your bike back and forth a bit. If you feel some extra movement on the bushings gap, you should tighten it, and the shutter under braking should disappear.

[cornucopia72]

Is it better to emphasis rear braking on a tandem?

We use front/rear:
50/50 (together) if trying to stop
1 - 3 (alternating) if trying to slow down while descending-turning with rear disc brake.
1 - 2 (alternating) if trying to slow down while descending-turning with rear rim brake.

[ljonesjo]

The headset is fine. It was the first thing I checked. The slop in the brakes on the posts is much more pronounced than a barely loose headset. That is why I asked if slop there is 'normal' for linear brakes.

[carrefour]

Also, check if your headset is properly tightened. If even a tiny bit loose, will create fork shudder when braking.
Because of short cable run, front brake is the best stopper. Discs are primarily on rear of tandem as front disc can create other issues.

Am very curious to hear which potential issues you see with disc in front? We ride a 2006 Cannondale mountain tandem and have the stock 203mm discs in front and rear (Avid ball bearing 7)... very happy with the complete bike and the brakes are definitely part of the happy picture. Powerful, reliable, easy to adjust. We live in Geneva Switzerland and I would not trust anything else on our alpine col descents on hot summer days. We are not exactly a heavy team at around 290 lbs for captain + stoker. But with rim brakes we would risk overheating-induced tire blowouts. Hydraulic discs would risk (even if only in extreme cases) brake locking due to bubbling hydraulic oil. Drum brake would decrease the fun of a "dynamic-sporty" decent. I prefer sufficient braking power available when needed, rather than keeping speed relatively low by using a drag brake. I agree that V-brakes would be lighter and that our setup would not be necessary for flat rides. Looking forward to your reply Zonatandem as I respect your huge tandem experience.

PS Avid brakepads are fine, but once used, I replace them with Koolstops as I believe they simply make the best brake pads on the market. Not too expensive and very smooth. I use Koolstop both on the tandem as on my race bike. So far they have been the only brake pads that my Ksyrium Elites (race bike) can stand. Anything else was eating the rims as if they were dessert.

[merlinextraligh]

What kind of fork does it have?

If the headset and the brakes are adjusted, and the rims are fine, then the shudder may be a function of flex in the fork.

[ljonesjo]

It is the stock fork that came with the bike, tandems specific cromoly. It seems very stout.